No correlation of tyrosinase mRNA in bone marrow with prognosis of metastatic melanoma.

BACKGROUND Recent publications suggest that tyrosinase mRNA in blood as well as in bone marrow is detectable only in a subgroup of patients with metastatic melanoma. OBJECTIVE We addressed the question, whether patients with metastatic melanoma and with RT-PCR-detectable tyrosinase mRNA in blood or bone marrow have a different prognosis compared to tyrosinase mRNA-negative patients. METHODS 20 melanoma patients with widespread clinical metastases were enrolled and the survival time after first diagnosis of visceral metastases was correlated to tyrosinase mRNA presence in blood and bone marrow samples. RESULTS The time of survival of 8 patients with metastatic melanoma and detectable tyrosinase mRNA in either blood or bone marrow was not different from the prognosis of 12 patients without detectable tyrosinase mRNA in either blood or bone marrow. CONCLUSION Although based on a limited number of patients our results suggest that detection of tyrosinase mRNA in blood or bone marrow samples of melanoma patients with advanced disease seems to have no substantial relevance for survival time and outcome of disease. For this purpose, detection of tyrosinase mRNA by RT-PCR is not a valid tumor marker. Nevertheless, tyrosinase positivity in bone marrow in earlier tumor stages might indicate increased risk for the development of distant metastases. This should be addressed in further studies.